266 SOILS: PROPERTIES AND MANAGEMENT 



as plant-food. The quantity of nutrient elements lost 

 annually from the average bare soil in a humid region 

 more than equals that withdrawn by a crop. The results 

 from the Rothamsted drain gauges 1 from 1871 to 1904 

 on a clay loam soil of three different depths are inter- 

 esting as to the light that they afford regarding actual 

 drainage losses : 



The rainfall and relative loss through the 40-inch depth 

 of soil is shown graphically in the following diagram : 



1 Hall, A. D. The Book of the Rothamsted Experiments, 

 23. London. 1905. 



